Series Hall Sensor Array for Extended Displacement Measurement
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Solution Overview
Problem
Conventional 3D Hall sensors have a limited displacement measurement range of 40 mm, which is insufficient for many applications, and their precision decreases with increasing distance from the sensor, leading to significant measurement errors at larger spacings.
Innovation Solution
A displacement sensor system utilizing multiple Hall sensors arranged in series and parallel, where the displacement measurement ranges of adjacent sensors overlap to extend the measurement range, with a learning routine to establish offset corrections and ensure a linear relationship between the position signal and the magnet's position, maintaining error within tolerable limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a single 3D Hall sensor is used, then the device complexity is low, but the displacement measurement range is limited to 40 mm
Solution Approach 1:
The displacement measurement system is segmented into multiple 3D Hall sensors, each responsible for a specific sub-range. By dividing the overall measurement range into segments handled by individual sensors, the total measurement range is extended while keeping each sensor's complexity manageable. The control unit coordinates these segmented measurements to provide comprehensive position information.
2Length of moving object
If the magnet is positioned far from the Hall sensor, then the displacement measurement range is extended, but the measurement precision decreases
Solution Approach 1:
By segmenting the measurement space into multiple zones, each handled by a dedicated Hall sensor, the system maintains high measurement precision within each zone while extending the overall measurement range. Each sensor operates optimally within its assigned range, avoiding the precision loss that would occur if a single sensor tried to measure across the entire extended range.
Solution Approach 2:
Different regions of the measurement space are assigned to different sensors based on their local measurement requirements. Each sensor is positioned and configured to provide optimal measurement quality for its specific local range, ensuring high precision wherever the magnet is located within the extended measurement range.
3Length of moving object
If multiple Hall sensors are arranged in series, then the displacement measurement range is extended, but the device complexity increases
Solution Approach 1:
The measurement system is divided into multiple sensor segments arranged in series along the movement axis. Each sensor handles a specific portion of the total range, and the control unit integrates these segmented measurements. This segmentation approach extends the measurement range while managing complexity through modular architecture.
Solution Approach 2:
Multiple Hall sensors perform the same measurement function but for different spatial ranges. This multi-functionality allows the system to maintain a uniform measurement approach across the entire extended range while using identical sensor technology, reducing the need for different types of components and simplifying the overall system design.
4Adaptability or versatility
If the displacement measurement range is extended beyond 40 mm, then the applicability increases, but the measurement error exceeds tolerable levels
Solution Approach 1:
The extended measurement range is divided into multiple segments, each handled by a dedicated Hall sensor. This segmentation ensures that measurement errors remain within tolerable levels for each individual segment while the cumulative effect provides an extended overall measurement range with controlled total error.
Solution Approach 2:
The system changes the operational parameters by using multiple sensors with different positional parameters along the movement axis. Each sensor is positioned to optimize measurements for its specific range, and the control unit coordinates these parameter variations to maintain overall measurement accuracy across the extended range.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system achieves a significantly extended displacement measurement range while maintaining precision and error control, allowing for accurate position determination over a broader range than conventional 3D Hall sensors.
Implementation Method 1
A typical example of a magnetic field sensor is the Hall sensor. By way of representation of a magnetic field sensor, the present invention is described with reference to a Hall sensor but is not limited thereto.
Data Source
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AI summary
The present invention relates to a displacement sensor for contactlessly measuring a position of a magnet relative to a reference point. The displacement sensor comprises the magnet which can be displaced along a movement axis, a plurality of magnetic field sensors which are arranged in series and which are arranged parallel with the movement axis of the magnet and a calculation unit for forming a position signal which indicates the position of the magnet relative to the reference point. The plurality of magnetic field sensors which are arranged in series are arranged in such a manner that the displacement measurement ranges of adjacent magnetic field sensors overlap in an overlap range. The calculation unit is constructed in such a manner that, if the position of the magnet is contained in an overlap range, it forms the position signal on the basis of output signals which are output by the magnetic field sensors whose displacement measurement ranges overlap in the overlap range; and, if the position of the magnet is not contained in an overlap range, it forms the position signal on the basis of the output signal which is output by the magnetic field sensor, in the displacement measurement range of which the magnet is located. The overlap range between two displacement measurement ranges of adjacent magnetic field sensors is selected in such a manner that the total error of the position signal formed by the calculation unit in that overlap range is smaller than a maximum tolerable error.